Improvement in surveying-instruments



1 2 Sheets-Sheet 1.

R. SCHNEIDER & F. W.. KRAFT.

SURVEYING INSTRUMENT. v N0.173,068. Patented Feb. 1, 1-876.

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wnunotr SCHNEIDER, orisncnn corms, nEAR-RossrTz, AND FREDERICK PATENTQFFTGE --WILLIAM KRAFT, OF VIENNA, AUSTRIA.

IMPROVEMENT m SURVEYING-INSTRUMENTS.

- Specification forming part of Letters Patent N 0. 173,068, datedFebruary 1, 1876; applicatign filed I January 11, 1876;. l I

-To all whom it may concern: I

Be it known that we, RUDoLF SCHNEIDER,

of Segen Gottes, nearRossitz, in Moravia: Em p1 re of Austria,'andFREDERICK WILLIAM KRAFT, of Vienna,Empir e of Austria, have invented anew and useful Improvement in. Instruments for Measuring Angles, ofwhich the following is aspecifioation: v

This invention relates to surveying-instruments, and more especially toinstruments to be used in mining-surveysfor measuring angles.

'ating all the difiiculties and delays arising from the deviation andthe variation of the compass-needle, and enabling the measurements to bemade more accurately and quickly.

The apparatus consists of two exactly similar instruments, which are tobe suspended separately on two stretched cords, and are connectedtogether, preferably, by means of a horseshoe-magnet attached tothe one,and a steel-plate attached to theot-her instrument. Each of these twininstruments consists of a graduated disk, a, divided into three hundredand sixty or four hundred degrees. This graduated disk is screwed to aplate, I), fixed to the lower part of a bent carrier, B. The upper partof this carrier B is provided with a round plate, 01, on which a doublearmed bracket, 0, is screwed'vertically and in a central position to thegraduated disk a. The bracket 0 is provided at its upper end with abox-head, f, through which a prismatic bar, E, passes vertically, andthis bar is toothed along its entire length, so that it can be fixed atany point by means of a thumb-screw, g. The box-head j is also providedwith a pinion, c, the teeth of which gear into the teeth of theprismatic bar E. By turning this pinion the relative position of thisrack E to the bracket-.0 can be varied at will. The rack E carries atone end a forked head, h, carrying the cross-arm D, which works on apin, i, in the fork h, and is provided with a suspensionhook, e and 6 ateach end. By means of these hooks the instrument can be suspended eitherdirect from the-cord, or indirectly from an intermediatesuspension-rail, F, hungto a a screw, g, is fitted,for'ming apivot-socket,

and opposite to this screw, in the upper part d of the carrier, a steelpin,'s, with conical socket, is fixed. These two sockets form thebearings for the pivot-pin l, to which a plate carrying the vernicrs a;y isfirmlyattached.

On this pivot-pin l the arm 1 turns, which forms the meansof'connecting' theone instrument with its twin instrument. Thisconnecting-arm consists of two parts, a and a, of

- unequal length. The shorter part n is pro- The construction is such asto render the: use of a compass unnecessary,- thereby obVi-' videdwith aweight,-in order to counterbalance the longer part M. This longer partit carries at its free end either a smooth magnetized steel plate, k, ora horseshoe-magnet,

z, with smooth contact-surfaces, the one of the twin instruments beingprovided with the steel plate, and the other with the magnet. Thevertical contact-surfaces of the steel-plate and the magnet are arrangedso as to bein the same plane as the axis of the plate carryingtheverniers. The turning-plate m,

which covers the entire graduated plate, ex- 'cept at two places, whereit is cut away, carries two verniers, w 1 which lie in the verticaldiameter of the arm n, and are graduated as desired. By means of anadjustingscrew, 0, fixed to the turning-plate m, the arm n can beslightly turned for the purpose of adjusting its position to thecross-direction of the verniers m y.. A spring, 7', fixed on the otherside, opposite to the adjusting-screw, aifords the necessary counterpressure.

When in use each instrument, is suspended by its hooks from anintermediate suspension.- r

rail hung to the cord. This suspension-rail F is provided with two hookstobe attached to the cord, and carries between two shoulders a wire, t,which can be stretched by suitable nuts. The instrument is hooked to thewire 52 name of the graduated plate is alone sufficient to insure itshorizontal position. These movable joints might evidently be alsoobtained by the use of knife-edges or pivot-points instead of apivot-pin and hooks. 1

The arrangement of the adjustable rack and --bracket is necessary, inorder to enable the twin instruments to be brought into the samehorizontal plane should the suspension-cords have to be fixed atdifi'erent heights.

Whatever angle is formed by the two suspension-cords will be indicatedby the graduated plates and verniers of the two instruments hanging fromthe cords, as the plates (alidades) carrying the verniers and connectedtogether, as described, turn on the fixed graduated plates differently,and, therefore indicate different degrees according to the differentrelative positions of the two instruments to each other.

The angle B d, formed by the two cords S S and S S, will, therefore, beequal to the angles 00+ y. In the instance shown in the drawings theangle .70 is twenty-seven and a half degrees, and 3 sixty-two and a halfdegrees; therefore the angle formed by the cord is ninety degrees. It isevident that the two cords S S and S S may be either of one single piecestretched round a hook at the point S, or of two separate piecescrossing each other.

We claim- I 1. An apparatus for measuring angles, consisting of two twininstruments, suspended separately, and having their Vernier platesconnected together by projecting arms, subfor the purposes set forth.

3. The connectingarms, with horseshoemagnet z, and magnetized plate It,substantially as and for the purposes set forth.

4. The swinging suspension arrangement, consisting of the fork h, pin1?,cross-bar D, books 6 0 ,01 their equivalents, in combination with thesuspension-rail F, or its equivalent, substantially as and for thepurposes described.

5. The arrangement for adjusting the level of each instrument, andconsisting of the rack E, pinion c, and fixing screw 9, or theirequivalents, substantially as and for the purposes described.

6. The suspension-rail F,.substantially as and for the purposesdescribed.

RUDOLF SCHNEIDER. FREDERICK WILLIAM KRAFT. Witnesses:

G. O. FAG-ET, F. BARTA.

